WCEC completed the construction of a 7-meter parabolic solar dish capable of concentrating the thermal energy of the sun up to 1,000 times.

The solar collector concentrates the thermal energy from the sun onto a receiver at the focal point. These all-in-one solar collectors can harvest more energy per area than photovoltaics.

WCEC will test their newly developed microchannel solar thermal receiver in combination with the solar collector dish. This receiver, when used with super critical carbon dioxide, is expected to absorb 100W per cm2 - a 66% improvement over the dish's existing receiver.

In Phase I of the project, WCEC completed the thermal characterization of flow through the microchannel passages of the receiver. In Phase II, WCEC will characterize the performance the microchannel receiver on this newly commissioned 7-meter parabolic solar dish.

Laboratory Testing of an Energy Efficient Dehumidifier for
Indoor Farms

Indoor farming operations do not require the typical ratio of air temperature (sensible cooling) and moisture content (latent cooling) required for residential or commercial buildings. In order to meet these specialized requirements, dehumidification systems are often necessary.

Traditional dehumidification systems provide dehumidification and increase the air temperature, as opposed to the desired dehumidification and reduction of air temperature. An alternative is MSP Technology’s dehumidification system that uses a plate air-to-air heat exchanger and a cooling coil that is part of a split compressor-based refrigeration system.

This process results in a ratio of sensible to latent cooling that is well suited for indoor farming applications. Experimental laboratory testing and numerical modeling were performed to estimate the annual energy savings produced by using the MSP Technology’s dehumidification system over a traditional dehumidification system. The results of this project forecast that implementation of MSP Technology’s system has potential to save 30% or more of the energy used for dehumidification and cooling in indoor farming applications.

In the interests of promoting energy efficiency and satisfying consumers, there has been a move toward automatic termination controllers in residential dryers, which use some method of sensing to determine when the load is dry. However, available test data shows that these control systems do not fare well when their energy efficiency performance is measured.

This project developed an automatic dryer cycle termination controller that utilized the relationship between dryer drum inlet temperatures and outlet temperatures to accurately predict the end of the drying cycle. The technology promises to be more accurate and robust in performance under different load and environmental conditions in comparison to existing technology. The low-cost automatic controller was demonstrated in the laboratory to reduce energy use in gas clothes dryers by accurately terminating the drying cycle. In addition, information obtained in the drying cycle can be used to predict real-time energy efficiency metrics to track dryer performance over time as a means for fault detection and to provide information to the consumer.

Evaporative cooling, combined with vapor-compression air conditioning is a promising technology for reducing cooling energy use and peak electricity demand. Although evaporative cooling offers substantial energy efficiency gains, it consumes water on site, which is a concern in drought impacted regions. Because generation of electricity also consumes water, net water consumption for evaporative cooling depends on the regional generation mix, water quality, and the water-use efficiency for particular evaporative equipment.

This webinar includes a detailed analysis of a theoretical worst-case scenario where all water for evaporative cooling is produced using energy-intensive desalination plants. The results show that evaporative cooling is energy and cost effective, even when the required water is produced by desalination. This webinar also summarizes recently-performed work that includes development of an ASHRAE standard for measuring the electricity savings and water use associated with evaporative pre-coolers for rooftop packaged equipment, results from numerous field studies of the energy savings and water use of hybrid vapor-compression/evaporative-cooling equipment, and exploration of the concept of using evaporative pre-coolers on vapor-compression condensers only during peak electricity demand periods.